Coaxial connector switch

ABSTRACT

A cover plate is attached to a switch portion of a coaxial connector. With this construction, even when the rising of flux due to surface tension occurs during a surface-mounting operation by reflow soldering, the flux is prevented from reaching the switch portion, thus preventing a disadvantage that the contact resistance is increased by the flux.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a coaxial connector switch, and moreparticularly to such a switch in which a cover plate is attached to aswitch portion of a coaxial connector so as to prevent the increase of acontact resistance of the switch portion of the coaxial connector due tothe intrusion of flux and also to prevent the intrusion of dust.

2. Description of the Related Art

There has been extensively used a coaxial connector switch which isconnected to an antenna on an automobile via a coaxial adapter,connected to the automobile antenna, so that the automobile antenna canbe used as an antenna of a portable cellular telephone.

FIG. 3 is a bottom view showing the construction of a conventionalcoaxial connector switch. FIG. 4 is a cross-sectional view taken alongthe line 4—4 of FIG. 3, showing the construction of the conventionalcoaxial connector switch.

The construction of the conventional coaxial connector switch will nowbe described with reference to FIGS. 3 and 4. In FIG. 4, a dielectricmember 21, in which a center pin 23 is inserted, is fitted on afunnel-shaped outer conductor 24. The center pin 23 is held in contactwith a first contact leg 26, including a resilient contact arm 25 havinga contact projection, and the center pin 23 is urged upward by aresilient force of the first contact leg 26.

The first contact leg 26 is contacted at its contact projection with asecond contact leg 27 so that a signal can be fed from the first contactleg 26 to the second contact leg 27. When the center pin 23 is pushed bya coaxial adapter 40, the signal can be fed from the first contact leg26 to the center pin 23. This will be described later.

Although not shown in FIG. 4, a terminal 28 of the first contact leg 26and a terminal 29 of the second contact leg 27 are mounted (surfacemounted) by reflow soldering on a conductor on a surface of a printedcircuit board. Also, first and second terminals 31 and 32 (shown in FIG.3), formed on the outer conductor 24, are mounted (surface mounted) onthe conductor of the printed circuit board by reflow soldering.

Next, the operation of the conventional axial connector switch will bedescribed with reference to FIG. 5. In FIG. 5, the coaxial adapter 40 ispushed into the coaxial connector switch in a direction of an arrow, acentral conductor 41 abuts against the center pin 21 to push the samedownward. As a result, the center pin 21 is moved downward against thebias of the first contact leg 26, so that the flow of the signal fromthe first contact leg 26 to the second contact leg 27 is interrupted.

At this time, an outer conductor 42 surrounding dielectric portion 43 ofthe coaxial adapter 40 is brought into contact with the outer conductor24 of the coaxial connector switch, so that signals from the terminals31 and 32, formed on the outer conductor 24 of the coaxial connectorswitch, are connected to the outer conductor 42 of the coaxial adapter40, and also the signal from the first contact leg 26 of the coaxialconnector.

As a result, the flow of the signal from the first contact leg 26 isswitched to the central conductor 41 of the coaxial adapter 40, andtherefore the automobile antenna can be used as an antenna of theportable cellular telephone.

In the above conventional coaxial connector switch, however, a coverplate is not provided at the switch portion of the coaxial connector;therefore, the rising of flux due to surface tension during thesurface-mounting operation by the reflow soldering can not be prevented,so that the contact resistance is increased by the flux, and in theworst case, there has been encountered a disadvantage that the switchportion has failed to function as a switch.

SUMMARY OF THE INVENTION

This invention seeks to solve the above problem, and an object of theinvention is to provide a coaxial connector switch in which the risingof flux during the surface-mounting operation by reflow soldering isprevented so that the contact resistance of the switch will not beincreased by the flux.

According to the first aspect of the invention, there is provided acoaxial connector switch wherein a dielectric member, in which a centerpin is inserted, is fitted on a funnel-shaped outer conductor, and thecenter pin is usually urged upward by a resilient arm, forming a switch;characterized in that a cover plate is attached to a switch portion of acoaxial connector so as to prevent the increase of a contact resistanceof the switch portion of the coaxial connector due to the intrusion offlux. There is achieved an advantage that the contact resistance of theswitch will not be increased by the flux.

According to the second aspect of the invention, there is provided acoaxial connector switch wherein a center pin is inserted, is fitted ona funnel-shaped outer conductor, and the center pin is usually urgedupward by a resilient arm, forming a switch; characterized in that acover plate is closely attached to a switch portion of a coaxialconnector so as to prevent the intrusion of dust into the switch portionof the coaxial connector. There are achieved advantages that dust willnot intrude into the switch portion from the exterior and that thecorrosion of switch contacts is prevented.

According to the third aspect of the invention, the coaxial connectorswitch is characterized in that cover plate is formed by the samematerial as that of the dielectric member. There is achieved anadvantage that the cover plate can be formed by the same material asthat of the dielectric member.

According to the fourth aspect of the invention, the cover plate of thecoaxial connector switch has a portion corresponding to the switchportion, which is smaller in thickness than a portion corresponding toterminal portions.

According to the fifth aspect of the invention, and the coaxialconnector switch is characterized in that a bottom end of the center pinis pointed. There is achieved an advantage that a load per unit area canbe increased; therefore, a first contact leg can be held in contact withthe center pin without increasing the resilient force of the firstcontact leg.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a bottom view showing the construction of a preferredembodiment of a coaxial connector switch of the invention.

FIG. 2 is a cross-sectional view taken along the line 2—2 of FIG. 1,showing the construction of the coaxial connector switch of theinvention.

FIG. 3 is a bottom view showing the construction of a conventionalcoaxial connector switch.

FIG. 4 is a cross-sectional view taken along the line 4—4 of FIG. 3,showing the construction of the conventional coaxial connector switch.

FIG. 5 is a cross-sectional view showing the operation of theconventional coaxial connector switch.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A preferred embodiment of the present invention will now be describedwith reference to FIGS. 1 and 2.

FIG. 1 is a bottom view showing the construction of an embodiment of acoaxial connector switch of the invention. FIG. 2 is a cross-sectionalview taken along the line A—A of FIG. 1, showing the construction of thecoaxial connector switch of this embodiment.

The construction of the coaxial connector switch of this embodiment willnow be described with reference to FIGS. 1 and 2. In FIG. 2, adielectric member 1, in which a center pin 3 is inserted, is fitted on afunnel-shaped outer conductor 4. The center pin 3 is held in contactwith a first contact leg 6, including a resilient contact arm 5, and thecenter pin 3 is urged upward by a resilient force of the first contactleg 6.

The first contact leg 6 has a flat distal end portion which is contactedwith a second contact leg 7 by the resilient force of the first contactleg 6 so that a signal can be fed from the first contact leg 6 to thesecond contact leg 7. When the center pin 3 is pushed by a coaxialadapter 40 of the same construction as described above, the signal canbe fed from the first contact leg 6 to the center pin 3. This operationis the same as described above for FIG. 5, and therefore explanationthereof will be omitted here.

Although not shown in FIG. 2, a terminal 8 of the first contact leg 6and a terminal 9 of the second contact leg 7 are mounted (surfacemounted) by reflow soldering on a conductor on a surface of a printedcircuit board. Also, first and second terminals 11 and 12 (shown in FIG.1), formed on the outer conductor 4, are mounted (surface mounted) onthe conductor of the printed circuit board by reflow soldering.

In the conventional construction of FIGS. 3 and 4, a cover plate is notprovided at the switch portion of the coaxial connector; therefore, therising of flux due to surface tension during the surface-mountingoperation by the reflow soldering can not be prevented, so that thecontact resistance is increased by the flux, and in the worst case,there has been encountered a disadvantage that the switch portion hasfailed to function as a switch. In this embodiment, however, a coverplate 2 is attached to the switch portion of the coaxial connector asshown in FIGS. 1 and 2; therefore, the above disadvantage can beprevented. In addition, a coaxial connector switch of this embodiment,the cover plate is formed by the same material as that of the dielectricmember. In the cover plate, thickness T1 corresponding to the switchportion, is smaller than thickness T2 corresponding to each terminalportion of the coaxial connector.

As shown in FIGS. 1 and 2, the cover plate 2 is closely attached to theswitch portion of the coaxial connector; therefore, the switch portionis not exposed to the exterior in contrast with the conventionalconstruction. Therefore, dust will not intrude into the switch portionfrom the exterior, and besides the corrosion of the switch contacts canbe prevented.

As shown in FIG. 2, the bottom end 3A of the center pin 3 is pointed,and with this construction a load per unit area can be increased;therefore, the first contact leg 6 can be held in contact with thecenter pin 3 without the need for increasing the resilient force of thefirst contact leg 6.

As described above, in the coaxial connector switch of the invention,the dielectric member, in which the center pin is inserted, is fitted onthe funnel-shaped outer conductor, and the center pin is usually urgedupward by the resilient arm, forming the switch, and this coaxialconnector switch is characterized in that the cover plate is attached tothe switch portion of the coaxial connector so as to prevent theincrease of the contact resistance of the switch portion of the coaxialconnector due to the intrusion of flux.

With this construction, there can be obtained the coaxial connectorswitch in which the increase of the contact resistance of the switchportion of the coaxial connector due to the intrusion of flux isprevented.

While only a certain embodiment of the invention has been specificallydescribed herein, it will be apparent that numerous modifications may bemade thereto without departing from the spirit and scope of theinvention.

The present invention is based on Japanese Patent Application No. Hei.11-186424 which is incorporated herein by reference.

What is claimed is:
 1. A coaxial connector switch comprising: afunnel-shaped conductor; a dielectric member fitted on saidfunnel-shaped conductor; a center pin inserted into said dielectricmember; a resilient arm capable of contacting with said center pin, sothat a switch portion is composed of both said center pin and saidresilient arm; and a cover plate attached to the switch portion.
 2. Thecoaxial connector switch according to claim 1, wherein said cover plateis closely attached to the switch portion.
 3. The coaxial connectorswitch according to claim 1, wherein said cover plate is formed by thesame material as that of said dielectric member.
 4. The coaxialconnector switch according to claim 2, wherein said cover plate isformed by the same material as that of said dielectric member.
 5. Thecoaxial connector switch according to claim 1, wherein said cover platehas a thin portion covering switch portion and smaller in thickness thana portion covering a terminal portion.
 6. The coaxial connector switchaccording to claim 2, wherein said cover plate has a thin portioncovering switch portion and smaller in thickness than a portion coveringa terminal portion.
 7. The coaxial connector switch according to claim1, wherein a bottom end of said center pin is pointed.
 8. The coaxialconnector switch according to claim 2, wherein a bottom end of saidcenter pin is pointed.
 9. A coaxial connector switch comprising: afunnel-shaped conductor; a dielectric member fitted on saidfunnel-shaped conductor; a center pin inserted into said dielectricmember; a resilient arm capable of contacting with said center pin, sothat a switch portion is composed of both said center pin and saidresilient arm; a circuit board attached to the switch portion; and aninsulator portion fitted over said switch portion and located betweensaid switch portion and said circuit board.